Oura Ring 4 - Silver

Oura Ring 4 - Silver - Size 9  Sleek, fully-titanium design and discreet sensors provide 24/7 comfort. With 5-8 days** of battery life per charge, never miss a beat when it comes to tracking your health. Track over 50 health and wellness metrics, and get personalized insights into your sleep, activity, stress, metabolic, heart health, and women’s health.  What's Included Oura Ring 4 Size-specific charger USB-C cable  Sensors Red and infrared LEDs measure blood oxygen levels Green and infrared LEDs alternate to measure heart rate and heart rate variability 24/7 and respiration rate Digital sensor measures temperature trends Accelerometer tracks movement and activity 24/7  Compatibility Supports metric and imperial units of measurement Integrates with 40+ apps Available on iOS and Android  Weight and Dimensions Width: 7.90mm Thickness: 2.88mm Weight: 3.3 to 5.2 grams (depending on Oura Ring size)  Battery Life 5-8 days of battery life** Typically charges in 20-80 minutes, depending on battery level  Quality Materials Non-allergenic titanium on inner & outer surfaces Seamless titanium interior Water resistant up to 100m/328 ft Minor scratches from regular wear are normal  Connectivity Bluetooth Low Energy Automatic firmware updates via Oura App EMF-safe  SEE PHOTOS OF ACTUAL RING! Used for less than a year. Some surface scratches. Factory reset and charged up. Works great!